Devices and methods for performing in-vivo imaging of passages or cavities within a body are known in the art. Such devices may include, inter alia, various endoscopic imaging systems and devices for performing imaging in various internal body cavities. Generally, these devices perform in-vivo imaging using an imager such as an imaging sensor array (e.g., a CMOS camera, although other types of imagers may be used) and an internal light source, such as for example a “white LED” or any other suitable light source, which supplies the light for illuminating the area which needs to be imaged. Light is reflected from the surface illuminated by the light source and an optical system focuses the reflected light onto the CMOS imaging sensor.
The optical system may include one or more optical elements, such as one or more lenses, one or more composite lens assemblies, one or more suitable optical filters, or any other suitable optical elements adapted for focusing an image on the imaging sensor and for manipulating light as is known in the art. The optical system may be attached to, or mounted on, or fabricated on or disposed adjacent to the imager light sensitive CMOS as is known in the art. The optical system and CMOS imaging sensor are typically accurately aligned to obtain proper focusing and optical use of the CMOS surface area. The small scale of parts makes it difficult to obtain proper alignment.
The combination of the light source, imaging array (e.g. CMOS) and optical focusing system may be referred to as an optical head. The optical head is commonly placed behind an optical window or dome to, for example, isolate its electric components from liquids found in a body, which may interfere with the operation of these components. For these optical systems it is advantageous to have the illuminating element and receiving means contained within a single compartment. Having a single optical window is advisable for hygienic and practical considerations as well.
A system having the illumination element and means for receiving reflected light contained behind a single optical window or dome may have back-scatter and stray light produced by light remitted from the optical window itself received by the receiving means.
There is therefore a need for a system having illumination elements and means for receiving reflected light behind a single optical window in which proper alignment is easily achieved and in which backscattered light is reduced.